The present invention relates to a variable displacement swash plate type compressor adapted for use in an air conditioning system for a vehicle, and more particularly to a lubricant pump coupled to one end of the drive shaft of the compressor to provide positive lubricant flow within the compressor and facilitate the lubrication of compressor components.
Variable displacement swash plate type compressors typically include a cylinder block provided with a number of cylinders, a piston disposed in each of the cylinders of the cylinder block, a crankcase sealingly disposed on one end of the cylinder block, a rotatably supported drive shaft, and a swash plate. The swash plate is adapted to be rotated by the drive shaft. Rotation of the swash plate is effective to reciprocatively drive the pistons. The length of the stroke of the pistons is varied by the inclination of the swash plate. Inclination of the swash plate is varied by controlling the pressure differential between a suction chamber and a crank chamber. The pressure differential is typically controlled using a control valve and an orifice tube which facilitates fluid communication between a discharge chamber and the crank chamber to convey compressed gases from the discharge chamber to the crank chamber based on pressure in a suction chamber.
The compressor arrangements of the prior art rely primarily on refrigerant flow to transport lubricant within the compressor. Therefore, ineffective lubrication of the close tolerance moving parts within the crank chamber occurs due to the lack of consistent flow of refrigerant gas from the discharge chamber to the crank chamber.
An object of the present invention is to produce a swash plate type compressor wherein positive lubricant flow within the compressor is achieved to result in improved lubrication of the compressor components.
The above, as well as other objects of the invention, may be readily achieved by a variable displacement swash plate type compressor comprising: a cylinder block having a plurality of cylinders arranged radially therein; a piston reciprocatively disposed in each of the cylinders of the cylinder block; a cylinder head attached to the cylinder block; a crankcase cooperating with the cylinder block to define a crank chamber; a drive shaft rotatably supported by the crankcase and the cylinder block; a swash plate adapted to be driven by the drive shaft, the swash plate having a central aperture for receiving the drive shaft, radially outwardly extending side walls, and a peripheral edge; and a lubricant pump coupled to one end of the drive shaft to provide positive lubricant flow within the compressor.